ShutterFinder vs ShuttR

Stop guessing your shutter speed on set. Point your iPhone at a flickering light, tap Measure, and ShutterFinder tells you the exact shutter speed that makes the flicker disappear in your footage. HOW IT WORKS ShutterFinder films the light at 240 frames per second, finds the flicker frequency with spectral analysis and turns it into a shutter speed for the frame rate you shoot at. It then checks the result at a second frame rate, which unmasks fast LED dimmers that would otherwise look like ordinary mains flicker. Within seconds you know what to set. WHAT IT MEASURES • LED panels and practicals, tube lights, HMIs, neon, monitors and TVs • LED dimmers (PWM) and OLED screens, including many that flicker too fast for the camera to see directly • 50 Hz and 60 Hz mains, anywhere in the world • Mixed lighting: when two lights flicker at different rates, the advice takes both into account and shows the alternative BUILT FOR THE SET • Shutter as time (1/50) or angle (180°), one tap to switch • 23.98, 24, 25, 29.97, 30, 50 and 60 fps, plus any custom frame rate • Change the frame rate after measuring and the advice updates instantly • When no flicker-free shutter exists at your frame rate, such as some tube lights at 60 fps, ShutterFinder says so and gives the setting that leaves the least flicker • Honest results: too dark, too shaky or no flicker at all is reported as exactly that, never as a guess • The circle marks exactly what is measured; tap anywhere to focus • Measuring stops by itself as soon as the reading is solid UNDER THE HOOD • 240 fps high-speed capture with automatic exposure bracketing for dark scenes • Verification at a second, and when needed a third, frame rate to resolve frequencies above what the camera sees directly • FFT analysis with Apple's Accelerate framework and sub-Hz precision • Mains frequencies locked to their exact values, so 100 Hz gives an exact 1/50 PRIVACY Everything is measured on your iPhone. No images or video are ever stored or sent. Anonymous usage statistics (no personal data, no tracking) help us improve the measurements. Requires iPhone XS or later with iOS 17 or later.

Is your analogue camera's shutter still accurate — or has it drifted after decades of use? ShuttR Check measures the real shutter speeds of your analog camera using nothing but your iPhone's camera and a light source. No hardware testers, no sensors to buy, no guesswork — reliably from 8s down to 1/500. HOW IT WORKS Open your camera's film back, remove the lens, and put a light source behind it. ShuttR Check uses your iPhone's high-speed camera to measure exactly how long each shutter release lets light through, then tells you how far that is from the speed you dialled in — in fractions of a stop. The app walks you through every step. There is nothing to configure, nothing to interpret: set up, release the shutter, read the result. RELIABLE FROM 8s TO 1/500 — ShuttR Check measures dependably from 8 seconds down to 1/500. An iPhone alone cannot resolve 1/1000 and up with an accuracy worth trusting, and we'd rather leave those speeds out than hand you numbers that look precise but aren't. That range also happens to cover where mechanical shutters drift the most and where a deviation actually shows up in your negatives. Timed speeds slower than 1s are there too, for the cameras that offer them. WHAT YOU GET A guided, step-by-step measurement protocol — no photography or technical background needed Automatic calibration (checks your room is dark enough and free of flickering light) Every speed compared against its nominal value, with the deviation in stops and a clear OK / deviation / defective verdict A history per camera, so you can track a shutter's condition over time A camera collection to track shutter's performance including import / export function of your camera list A shareable "shutter checked" certificate (image or PDF) — perfect for camera sellers on eBay, Etsy, or classifieds, showing buyers exactly what they're getting SHUTTER TYPES Horizontal and vertical focal-plane shutters are tested and validated — these are the shutters in most classic SLRs and rangefinders. Leaf (central) shutters should work just as well, since the app measures the light pulse itself and doesn't care how the shutter produces it, but they haven't been through the same validation, so treat those readings as unconfirmed. WHAT THIS APP IS NOT ShuttR Check gives you dependable, repeatable information about how far your shutter speeds have drifted. It does not replace a calibrated measuring instrument, and the results are not a laboratory reference — if you need certified figures, a service technician with proper equipment is still the right call. It also does not measure shutter capping. The app times how long light passes through, not how evenly the curtains expose across the frame. A shutter that tapers or caps at one edge can still show correct overall timing here. WHO IT'S FOR Film photographers who want to know if their gear is actually accurate Camera collectors curious about a new find Sellers who want to offer buyers real proof of a working shutter